#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=70;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL c[maxn];
int main(void){
   cin.tie(0);std::ios::sync_with_stdio(false);
   LL a,b,k;cin>>a>>b>>k;
   for(LL i=1;i<=a;i++) c[i]=0;
   for(LL i=a+1;i<=a+b;i++) c[i]=1;
   k--;
   bool flag=1;
   while(flag){
       bool ok=1;
       for(LL i=1;i<=a;i++){
           if(c[i]!=1) {ok=0;break;}
       }
       if(ok) flag=0;
       if(k==0) flag=0;
       if(flag==0) break;
       for(LL i=a+b;i-1>=1;i--){
           if(c[i]==1&&c[i-1]!=1){
               LL num=0;
               for(LL j=i+1;j<=a+b;j++){
                   if(c[j]==1) num++;
               }
               for(LL j=a+b;j>=i+1;j--){
                   if(num) c[j]=1,num--;
                   else c[j]=0;
               }
               swap(c[i],c[i-1]);
               k--;
               break;
           }
       }

   }
   for(LL i=1;i<=a+b;i++){
       if(c[i]==1) cout<<"b";
       else cout<<"a";
   }
   cout<<"\n";
   return 0;
}
